The need for a mass screening technique for the early diagnosis of lung cancer is well established. Our current work in physiologic data acquisition from medical fluoroscopy strongly suggests that videodensitometry coupled to video disc recorded fluoroscopy can provide a method for the early detection of lung cancer in the general population. Using videodensitometric evaluation techniques which we have developed, it is possible to assess pulmonary perfusion simply from video recorded fluoroscopy of the patients' lung fields. There is sufficient evidence in the prior literature to suggest that this perfusion pulsation significantly changes in the presence of early carcinoma of the lung. Coupling our measurement techniques to video disc recorded fluoroscopy will decrease the radiation dose to the patient so dramatically that this technique should be acceptable as a mass screening procedure for the early diagnosis of lung cancer.